Establishing a Standardized DNA Extraction Method Using NaCl from Oral Mucosa Cells for Its Application in Imprinting Diseases Such as Prader-Willi and Angelman Syndromes: A Preliminary Investigation.

BACKGROUND: Diagnosing imprinting defects in neonates and young children presents challenges, often necessitating molecular analysis for a conclusive diagnosis. The isolation of genetic material from oral swabs becomes crucial, especially in settings where blood sample collection is impractical or for vulnerable populations like newborns, who possess limited blood volumes and are often too fragile for invasive procedures. Oral swab samples emerge as an excellent source of DNA, effectively overcoming obstacles associated with rare diseases. METHODS: In our study, we specifically addressed the determination of the quality and quantity of DNA extracted from oral swab samples using NaCl procedures. RESULTS: We compared these results with extractions performed using a commercial kit. Subsequently, the obtained material underwent MS-HRM analysis for loci associated with imprinting diseases such as Prader-Willi and Angelman syndromes. CONCLUSIONS: Our study emphasizes the significance of oral swab samples as a reliable source for obtaining DNA for MS-HRM analysis. NaCl extraction stands out as a practical and cost-effective method for genetic studies, contributing to a molecular diagnosis that proves particularly beneficial for patients facing delays in characterization, ultimately influencing their treatment.

Predictors of bleeding and thrombotic events among patients admitted to the hospital with COVID-19 and elevated D-dimer: insights from the ACTION randomized clinical trial.

Therapeutic anticoagulation showed inconsistent results in hospitalized patients with COVID-19 and selection of the best patients to use this strategy still a challenge balancing the risk of thrombotic and hemorrhagic outcomes. The present post-hoc analysis of the ACTION trial evaluated the variables independently associated with both bleeding events (major bleeding or clinically relevant non-major bleeding) and the composite outcomes thrombotic events (venous thromboembolism, myocardial infarction, stroke, systemic embolism, or major adverse limb events). Variables were assessed one by one with independent logistic regressions and final models were chosen based on Akaike information criteria. The model for bleeding events showed an area under the curve of 0.63 (95% confidence interval [CI] 0.53 to 0.73), while the model for thrombotic events had an area under the curve of 0.72 (95% CI 0.65 to 0.79). Non-invasive respiratory support was associated with thrombotic but not bleeding events, while invasive ventilation was associated with both outcomes (Odds Ratio of 7.03 [95 CI% 1.95 to 25.18] for thrombotic and 3.14 [95% CI 1.11 to 8.84] for bleeding events). Beyond respiratory support, creatinine level (Odds Ratio [OR] 1.01 95% CI 1.00 to 1.02 for every 1.0 mg/dL) and history of coronary disease (OR 3.67; 95% CI 1.32 to 10.29) were also independently associated to the risk of thrombotic events. Non-invasive respiratory support, history of coronary disease, and creatinine level may help to identify hospitalized COVID-19 patients at higher risk of thrombotic complications.ClinicalTrials.gov: NCT04394377.

Perfil e impacto dos bolsistas de produtividade em pesquisa do CNPq da Faculdade de Medicina da UFMG / Profile and impact of CNPq research productivity fellows at the Faculty of Medicine of UFMG

INTRODUÇÃO: Os programas de iniciação científica e pós-graduação são um instrumento essencial na formação de recursos humanos e na perpetuação da produção científica nacional. O papel dos professores pesquisadores no adequado desenvolvimento científico dos estudantes de graduação e pós-graduação tem sido continuamente reafirmado em diversas pesquisas sobre a qualidade do ensino superior brasileiro, apesar da contínua desvalorização das universidades públicas no país. Avaliar a carreira e o perfil dos bolsistas de produtividade em pesquisa pode fornecer elementos em relação ao impacto desses profissionais no ensino, na pesquisa e na internacionalização das universidades. OBJETIVO: Caracterizar o perfil profissional e a produção científica dos bolsistas do Programa de Produtividade em Pesquisa da Faculdade de Medicina da Universidade Federal de Minas Gerais. MÉTODOS: Estudo descritivo baseado na análise de dados públicos disponíveis na Plataforma Lattes. Os bolsistas de produtividade em pesquisa foram apurados com base nos resultados dos editais de 2013, 2016 e 2019. RESULTADOS: A análise das variáveis evidenciou diminuição do número de docentes bolsistas da instituição, que passou de 34 para 29. Observamos um número significativamente maior de projetos financiados por profissionais do sexo masculino quando comparados às pesquisadoras (p=0,03) e uma forte correlação entre os anos de doutorado e o número de doutores orientados que atualmente se dedicam à pesquisa. CONCLUSÃO: Professores pesquisadores exercem impacto direto na formação de recursos humanos qualificados e na formação de recursos humanos qualificados e na internacionalização das universidades públicas.

INTRODUCTION: Mentoring through scientific initiation and post-graduate programs are an essential instrument on the formation of human resources and the perpetuation of national scientific production. The role of research professors in the proper scientific development of graduate and post-graduate medical students has been continuously reaffirmed in several surveys on the quality of Brazilian superior education, despite the continuous desvalorization of higher education in the country. Determine the career and profile of research productivity fellows could measure the impact of these professionals in teaching, researching and internationalization of our university. OBJECTIVE: To characterize the professional profile and scientific production of the Productivity in Research Program fellows from the Faculty of Medicine of the Federal University of Minas Gerais. METHODS: This descriptive study is based on the analysis of public data available at Lattes Platform. Research productivity fellows were determined based on the results of the 2013, 2016 and 2019 calls for tenders. RESULTS: Analysis of the variables showed a decrease in the number of professors with scholarships at the institution, which went from 34 to 29. We observed a significantly higher number of funded projects of male professionals when compared to female researchers (p=0.03) and a strong correlation between years of doctorate degree and the number of mentored doctors currently dedicating to research. CONCLUSION: Experient research professors exert direct impact on the formation of qualified human resources and the internationalization of the federal university.

Factors associated with pulmonary infection in kidney and kidney-pancreas transplant recipients: a case-control study.

OBJECTIVE: To evaluate the etiology of and factors associated with pulmonary infection in kidney and kidney-pancreas transplant recipients. METHODS: This was a single-center case-control study conducted between December of 2017 and March of 2020 at a referral center for kidney transplantation in the city of Belo Horizonte, Brazil. The case:control ratio was 1:1.8. Cases included kidney or kidney-pancreas transplant recipients hospitalized with pulmonary infection. Controls included kidney or kidney-pancreas transplant recipients without pulmonary infection and matched to cases for sex, age group, and donor type (living or deceased). RESULTS: A total of 197 patients were included in the study. Of those, 70 were cases and 127 were controls. The mean age was 55 years (for cases) and 53 years (for controls), with a predominance of males. Corticosteroid use, bronchiectasis, and being overweight were associated with pulmonary infection risk in the multivariate logistic regression model. The most common etiologic agent of infection was cytomegalovirus (in 14.3% of the cases), followed by Mycobacterium tuberculosis (in 10%), Histoplasma capsulatum (in 7.1%), and Pseudomonas aeruginosa (in 7.1%). CONCLUSIONS: Corticosteroid use, bronchiectasis, and being overweight appear to be risk factors for pulmonary infection in kidney/kidney-pancreas transplant recipients, endemic mycoses being prevalent in this population. Appropriate planning and follow-up play an important role in identifying kidney and kidney-pancreas transplant recipients at risk of pulmonary infection.

Factors associated with pulmonary infection in kidney and kidney-pancreas transplant recipients: a case-control study / Fatores associados a infecção pulmonar em pacientes que receberam transplante de rim ou rim-pâncreas: estudo de caso-controle

ABSTRACT Objective: To evaluate the etiology of and factors associated with pulmonary infection in kidney and kidney-pancreas transplant recipients. Methods: This was a single-center case-control study conducted between December of 2017 and March of 2020 at a referral center for kidney transplantation in the city of Belo Horizonte, Brazil. The case:control ratio was 1:1.8. Cases included kidney or kidney-pancreas transplant recipients hospitalized with pulmonary infection. Controls included kidney or kidney-pancreas transplant recipients without pulmonary infection and matched to cases for sex, age group, and donor type (living or deceased). Results: A total of 197 patients were included in the study. Of those, 70 were cases and 127 were controls. The mean age was 55 years (for cases) and 53 years (for controls), with a predominance of males. Corticosteroid use, bronchiectasis, and being overweight were associated with pulmonary infection risk in the multivariate logistic regression model. The most common etiologic agent of infection was cytomegalovirus (in 14.3% of the cases), followed by Mycobacterium tuberculosis (in 10%), Histoplasma capsulatum (in 7.1%), and Pseudomonas aeruginosa (in 7.1%). Conclusions: Corticosteroid use, bronchiectasis, and being overweight appear to be risk factors for pulmonary infection in kidney/kidney-pancreas transplant recipients, endemic mycoses being prevalent in this population. Appropriate planning and follow-up play an important role in identifying kidney and kidney-pancreas transplant recipients at risk of pulmonary infection.

RESUMO Objetivo: Avaliar a etiologia da infecção pulmonar e os fatores a ela associados em pacientes que receberam transplante de rim ou rim-pâncreas. Métodos: Estudo unicêntrico de caso-controle realizado entre dezembro de 2017 e março de 2020 em um centro de referência em transplantes de rim em Belo Horizonte (MG). A proporção caso:controle foi de 1:1,8. Os casos foram pacientes que haviam recebido transplante de rim ou rim-pâncreas e que foram hospitalizados em virtude de infecção pulmonar. Os controles foram pacientes que haviam recebido transplante de rim ou rim-pâncreas e que não apresentaram infecção pulmonar, emparelhados com os casos pelo sexo, faixa etária e tipo de doador (vivo ou falecido). Resultados: Foram incluídos no estudo 197 pacientes. Destes, 70 eram casos e 127 eram controles. A média de idade foi de 55 anos (casos) e 53 anos (controles), com predomínio de pacientes do sexo masculino. O uso de corticosteroides, bronquiectasias e sobrepeso relacionaram-se com risco de infecção pulmonar no modelo de regressão logística multivariada. O agente etiológico de infecção mais comum foi o citomegalovírus (em 14,3% dos casos), seguido de Mycobacterium tuberculosis (em 10%), Histoplasma capsulatum (em 7,1%) e Pseudomonas aeruginosa (em 7,1%). Conclusões: O uso de corticosteroides, bronquiectasias e sobrepeso parecem ser fatores de risco de infecção pulmonar em pacientes que receberam transplante de rim ou rim-pâncreas, e as micoses endêmicas são prevalentes nessa população. O planejamento e acompanhamento adequados desempenham um papel importante na identificação de pacientes transplantados de rim/rim-pâncreas nos quais haja risco de infecção pulmonar.

Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D-dimer concentration (ACTION): an open-label, multicentre, randomised, controlled trial.

BACKGROUND: COVID-19 is associated with a prothrombotic state leading to adverse clinical outcomes. Whether therapeutic anticoagulation improves outcomes in patients hospitalised with COVID-19 is unknown. We aimed to compare the efficacy and safety of therapeutic versus prophylactic anticoagulation in this population. METHODS: We did a pragmatic, open-label (with blinded adjudication), multicentre, randomised, controlled trial, at 31 sites in Brazil. Patients (aged ≥18 years) hospitalised with COVID-19 and elevated D-dimer concentration, and who had COVID-19 symptoms for up to 14 days before randomisation, were randomly assigned (1:1) to receive either therapeutic or prophylactic anticoagulation. Therapeutic anticoagulation was in-hospital oral rivaroxaban (20 mg or 15 mg daily) for stable patients, or initial subcutaneous enoxaparin (1 mg/kg twice per day) or intravenous unfractionated heparin (to achieve a 0·3-0·7 IU/mL anti-Xa concentration) for clinically unstable patients, followed by rivaroxaban to day 30. Prophylactic anticoagulation was standard in-hospital enoxaparin or unfractionated heparin. The primary efficacy outcome was a hierarchical analysis of time to death, duration of hospitalisation, or duration of supplemental oxygen to day 30, analysed with the win ratio method (a ratio >1 reflects a better outcome in the therapeutic anticoagulation group) in the intention-to-treat population. The primary safety outcome was major or clinically relevant non-major bleeding through 30 days. This study is registered with ClinicalTrials.gov (NCT04394377) and is completed. FINDINGS: From June 24, 2020, to Feb 26, 2021, 3331 patients were screened and 615 were randomly allocated (311 [50%] to the therapeutic anticoagulation group and 304 [50%] to the prophylactic anticoagulation group). 576 (94%) were clinically stable and 39 (6%) clinically unstable. One patient, in the therapeutic group, was lost to follow-up because of withdrawal of consent and was not included in the primary analysis. The primary efficacy outcome was not different between patients assigned therapeutic or prophylactic anticoagulation, with 28 899 (34·8%) wins in the therapeutic group and 34 288 (41·3%) in the prophylactic group (win ratio 0·86 [95% CI 0·59-1·22], p=0·40). Consistent results were seen in clinically stable and clinically unstable patients. The primary safety outcome of major or clinically relevant non-major bleeding occurred in 26 (8%) patients assigned therapeutic anticoagulation and seven (2%) assigned prophylactic anticoagulation (relative risk 3·64 [95% CI 1·61-8·27], p=0·0010). Allergic reaction to the study medication occurred in two (1%) patients in the therapeutic anticoagulation group and three (1%) in the prophylactic anticoagulation group. INTERPRETATION: In patients hospitalised with COVID-19 and elevated D-dimer concentration, in-hospital therapeutic anticoagulation with rivaroxaban or enoxaparin followed by rivaroxaban to day 30 did not improve clinical outcomes and increased bleeding compared with prophylactic anticoagulation. Therefore, use of therapeutic-dose rivaroxaban, and other direct oral anticoagulants, should be avoided in these patients in the absence of an evidence-based indication for oral anticoagulation. FUNDING: Coalition COVID-19 Brazil, Bayer SA.

Optimization of Expression and Purification of Schistosoma mansoni Antigens in Fusion with Rhizavidin.

Schistosomiasis causes significant morbidity and mortality. Vaccine efforts to date indicate the need to increase the immunogenicity of Schistosoma antigens. The multiple antigen-presenting system, whereby proteins are genetically fused to rhizavidin and affinity linked to biotinylated templates, enables the generation of robust immune responses. The objective of this work was to express and purify the S. mansoni antigens, SmTSP-2 and SmCD59.2, in fusion with rhizavidin. The fusion with rhizavidin greatly decreased the expression level of rSmTSP-2, but not rSmCD59.2, and both were expressed in the insoluble fraction, requiring optimization of culture conditions. Evaluation of different E. coli strains and media showed that BL21-DE3 cultured in Terrific Broth provided the highest expression levels of both proteins. Investigation of a range of time and temperature of induction showed that E. coli strains expressing rRzv:SmTSP-2 and rRzv:SmCD59.2 showed the highest protein production at 23 °C for 15 h. Recombinant proteins were purified by a single step of affinity chromatography allowing isolation of these proteins in high concentration and purity. The optimization process increased final soluble protein yield of rRzv:SmTSP-2 by fourfold and rRzv:SmCD59.2 by tenfold, providing ~ 20 mg/L of each protein. Optimized fusion protein production will allow antigen use in biotin-rhizavidin affinity platforms.

[Anesthesia for a cesarean section on a pregnant patient with Cockayne syndrome: case report]. / Anestesia para cesárea em gestante com síndrome de Cockayne: relato de caso.

Cockayne syndrome is an autosomal recessive multi-systemic disorder due to DNA repair failure. It was originally described in 1936 in children of small stature, retinal atrophy and deafness, characterized by dwarfism, cachexia, photosensitivity, premature aging and neurologic deficits. The most typical feature is described as birdlike facies: protruding maxilla, facial lipoatrophy, sunken eyes, large ears and thin nose. Difficult airway management with subglottic stenosis and risk of gastric content aspiration has been described. Although the clinical characteristics of Cockayne syndrome have been well described in pediatric publications, there is only one report in the literature on anesthesia for an obstetric patient. We report the case of a pregnant patient diagnosed with Cockayne syndrome, submitted successfully to spinal anesthesia for a cesarean section due to cephalopelvic disproportion. In view of the difficult decision between inducing general anesthesia in a patient with a likely difficult airway, or neuraxial anesthesia in a patient with cardiovascular, respiratory and neurocognitive limitations, we suggest tailored management to reach the best results for the mother and newborn.

Anesthesia for a cesarean section on a pregnant patient with Cockayne syndrome: case report / Anestesia para cesárea em gestante com síndrome de Cockayne: relato de caso

Abstract Cockayne syndrome is an autosomal recessive multi-systemic disorder due to DNA repair failure. It was originally described in 1936 in children of small stature, retinal atrophy and deafness, characterized by dwarfism, cachexia, photosensitivity, premature aging and neurologic deficits. The most typical feature is described as birdlike facies: protruding maxilla, facial lipoatrophy, sunken eyes, large ears and thin nose. Difficult airway management with subglottic stenosis and risk of gastric content aspiration has been described. Although the clinical characteristics of Cockayne syndrome have been well described in pediatric publications, there is only one report in the literature on anesthesia for an obstetric patient. We report the case of a pregnant patient diagnosed with Cockayne syndrome, submitted successfully to spinal anesthesia for a cesarean section due to cephalopelvic disproportion. In view of the difficult decision between inducing general anesthesia in a patient with a likely difficult airway, or neuraxial anesthesia in a patient with cardiovascular, respiratory and neurocognitive limitations, we suggest tailored management to reach the best results for the mother and newborn.

Resumo A síndrome de Cockayne é doença multissistêmica autossômica recessiva devido à falha no reparo do DNA. Originalmente descrita em 1936 em crianças com baixa estatura, atrofia retiniana e surdez, é caracterizada por nanismo, caquexia, fotossensibilidade, envelhecimento acelerado e déficits neurológicos. O mais típico é a fácies, descrita como similar à de um pássaro: maxila proeminente, atrofia do coxim adiposo bucal, olhos profundos, orelhas grandes e nariz fino. Tem sido descrita dificuldade no manejo da via aérea com estreitamento subglótico e risco de aspiração gástrica. Embora as características clínicas da síndrome de Cockayne sejam bem relatadas em publicações pediátricas, há apenas um relato de anestesia em paciente obstétrica na literatura. Relatamos o caso de gestante com diagnóstico de síndrome de Cockayne, submetida com sucesso a raquianestesia para parto cesariano por desproporção cefalopélvica. Diante da difícil decisão entre induzir anestesia geral em paciente com provável via aérea difícil ou anestesia neuroaxial, em meio a limitações cardiovasculares, respiratórias e neurocognitivas da paciente, conduta individualizada é sugerida para alcançar os melhores resultados para a gestante e o neonato.

Investigação genética e epigenética em pacientes com Síndrome de Beckwith-Wiedemann / Genetic and epigenetic research in patients with Beckwith-Wiedemann Syndrome

Os erros no padrão de imprinting são caracterizados como alterações epigenéticas por não afetarem a sequência nucleotídica do DNA mas modificarem a expressão gênica. Diversos aspectos do desenvolvimento embrionário, incluindo ocorrência de malformações congênitas e síndromes diversas, como a síndrome de Beckwith-Wiedemann (SBW; OMIM#130650) ocorrem em decorrência de eventos epigenéticos. A etiologia molecular de SBW é descrita com base em alterações epigenéticas na região cromossômica 11p15.5, que possui genes cuja expressão é regulada por dois centros de imprinting (IC) ou regiões diferencialmente metiladas (DMR). O IC1, que controla a expressão dos genes IGF2 e H19 apresenta metilação no alelo paterno e ausência de metilação no alelo materno; o IC2 encontra-se metilado normalmente no alelo materno, participando no controle da expressão dos genes CDKN1C, KCNQ1 e KNCQ1OT1. A etiologia de SBW também está associada a mutações pontuais em genes como CDKN1C, que codifica um inibidor de kinase dependente de ciclina da fase G1 do ciclo celular. O objetivo deste trabalho é investigar alterações genéticas e epigenéticas em amostras de DNA de 21 pacientes com SBW oriundos do Ambulatórido de Genética Médica do Instituto Nacional Fernandes Figueira IFF/FIOCRUZ. A abordagem metodológica consistiu na análise do perfil de metilação dos dois centros de imprinting de 11p15.5 com uso da ténica de MS-MLPA; análise de microssatélites dessa região, visando discriminar alterações epigenéticas em ambos os centros de imprinting de possíveis dissomias uniparentais (UPD); e a amplificação do gene CDKN1C, para sequenciamento de Sanger. Dos 21 pacientes analisados inicialmente por MS-MLPA, sete não apresentaram nenhuma alteração epigenética. Após reavaliação clínica foi confirmado o diagnóstico de SBW em três desses sete pacientes enquanto que os outros quatro pacientes apresentaram características clínicas isoladas associadas à SBW, sendo excluídos da amostra. Nos 14 pacientes restantes a análise de MS-MLPA identificou 10 casos de perda isolada de metilação no IC2, três casos de deleção em IC2 e um caso de ganho de metilação em IC1 com perda em IC2 (UPDp). Este trabalho confirmou estudos anteriores sobre a ocorrência de alterações epignéticas nesta síndrome; em consequência, permitindo uma orientação clínica e antecipação do monitoramento de pacientes quanto ao risco de tumores pediátricos.

Errors in imprinting pattern are characterized as epigenetic alterations, not affecting the nucleotide sequencing on DNA but affecting the gene expression. Several aspects of embrionary development, including occurrence of abnormalities and congenital disorders, as Beckwith-Wiedemann syndrome (BWS; OMIM#130650) occur due epignetics events. The molecular etiology of SBW is described based on epigenetic alterations in 11p15.5 chromossomic region, wich includes genes that have the expression regulated by two imprinting centers (IC) or differentialy methylated region (DMR). The IC1 regulates the gene expression of IGF2 and H19 genes. This IC shows a high methylation level only in the paternal allele. The IC2, normally methylated on the maternal allele, controls de gene expression of CDKN1C, KCNQ1 e KNCQ1OT1 genes. Besides this alterations, SBW's etiology is also associated with pontual mutations in CDKN1C gene, which encondes a cyclin dependent kinase inhibitor, acting on G1 celular cycle phase. The purpose of this study is to investigate genetics and epigenetics alterations in DNA samples of 21 patients with BWS from Instituto Nacional Fernandes Figueira IFF/FIOCRUZ. The methodological approach was based on the methylation profile's analysis of the two 11p15.5 imprinting centers using the MS-MLPA technique; microsatellite analysis of this region, aiming to distinguish epigenetic alterations on both imprinting centers from possible uniparental disomy (UPD); and CDKN1C gene Sanger sequencing. Seven of 21 patients analysed by MS-MLPA did not shown any epigenetic alteration. After a clinical revaluation the SBW diagnosys was confirmed to three of this sevens patients while the reamining four only shown isolated clinial features associated with BWS. On 14 patients MS-MLPA analysis identified 10 cases of isolated loss of methylation on IC2, three cases of IC2 deletions and one case with both gain of methylation on IC1 and loss of methylation on IC2 (UDPp). This study confirmed previous researches about the epigenetic alteration occurence ih BWS; in consequence, allowing a clinical monitoring to this patients due the risk of pediatric tumors.

Epileptiform activity and behavioral arrests in mice overexpressing the calcium channel subunit α2δ-1.

The alpha2delta-1 subunit (α2δ-1) of voltage-gated calcium channels is a receptor for astrocyte-secreted thrombospondins that promote developmental synaptogenesis. Alpha2delta-1 receptors are upregulated in models of injury-induced peripheral pain and epileptogenic neocortical trauma associated with an enhancement of excitatory synaptic connectivity. These results lead to the hypothesis that overexpression of α2δ-1 alone in neocortex of uninjured transgenic (TG) mice might result in increased excitatory connectivity and consequent cortical hyperexcitability and epileptiform activity. Whole cell recordings from layer V pyramidal neurons in somatosensory cortical slices of TG mice showed increased frequency and amplitude of miniature and spontaneous EPSCs and prolonged bursts of polysynaptic EPSCs. Epileptiform field potentials were evoked in layers II/III and V of brain slices from TG mice, but not controls. Dual immunoreactivity for Vglut-2 and PSD95 showed increased density of close appositions in TG mice compared to controls, suggesting an increased number of excitatory synapses. Video-EEG monitoring showed that 13/13 implanted TG mice aged >P21, but not controls, had frequent abnormal spontaneous epileptiform events, consisting of variable duration, high amplitude bi-hemispheric irregular bursts of delta activity, spikes and sharp waves lasting many seconds, with a variable peak frequency of ~1-3Hz, associated with behavioral arrest. The epileptiform EEG abnormalities and behavioral arrests were reversibly eliminated by treatment with i.p. ethosuximide. Behavioral seizures, consisting of ~15-30s duration episodes of rigid arched tail and head and body extension, followed by loss of balance and falling, frequently occurred in adult TG mice during recovery from isoflurane-induced anesthesia, but were rare in WT mice. Results show that over-expression of α2δ-1 subunits increases cortical excitatory connectivity and leads to neocortical hyperexcitability and epileptiform activity associated with behavioral arrests in adult TG mice. Similar increases in expression of α2δ-1 in models of cortical injury may play an important role in epileptogenesis. SIGNIFICANCE: Binding of astrocytic-secreted thrombospondins to their α2δ-1 receptor facilitates excitatory synapse formation and excitatory transmission during cortical development and after injury. Upregulation of α2δ-1 is present in models of injury-induced pain and epileptogenic cortical trauma, along with many other molecular alterations. Here we show that overexpression of α2δ-1 alone in TG mice can enhance excitatory connectivity in neocortex and lead to neural circuit hyperexcitability and episodes of electrographic epileptiform activity, associated with behavioral arrests in transgenic mice. α2δ-1 is the high-affinity receptor for gabapentinoids and a potential target for prophylactic treatment of posttraumatic epilepsy and other disorders in which excessive aberrant excitatory connectivity is a pathophysiological feature.

First report of Y-linked genes in the kissing bug Rhodnius prolixus.

BACKGROUND: Due to an abundance of repetitive DNA, the annotation of heterochromatic regions of the genome such as the Y chromosome is problematic. The Y chromosome is involved in key biological functions such as male-fertility and sex-determination and hence, accurate identification of its sequences is vital. The hemipteran insect Rhodnius prolixus is an important vector of Chagas disease, a trypanosomiasis affecting 6-7 million people worldwide. Here we report the identification of the first Y-linked genes of this species. RESULTS: The R. prolixus genome was recently sequenced using separate libraries for each sex and the sequences assembled only with male reads are candidates for Y linkage. We found 766 such candidates and PCR tests with the ten largest ones, confirmed Y-linkage for all of them, suggesting that "separate libraries" is a reliable method for the identification of Y-linked sequences. BLAST analyses of the 766 candidate scaffolds revealed that 568 scaffolds contained genes or part of putative genes. We tested Y-linkage for 36 candidates and found that nine of them are Y-linked (the PCR results for the other 25 genes were inconclusive or revealed autosomal/X-linkage). Hence, we describe in this study, for the first time, Y-linked genes in the R. prolixus genome: two zinc finger proteins (Znf-Y1 and Znf-Y2), one metalloproteinase (Met-Y), one aconitase/iron regulatory protein (Aco-Y) and five genes devoid of matches in any database (Rpr-Y1 to Rpr-Y5). Expression profile studies revealed that eight genes are expressed mainly in adult testis (some of which presented a weak expression in the initial developmental stages), while Aco-Y has a gut-restricted expression. CONCLUSIONS: In this study we showed that the approach used for the R. prolixus genome project (separate sequencing of male and female DNA) is key to easy and fast identification of sex-specific (e.g. Y chromosome sequences). The nine new R. prolixus Y-linked genes reported here provide unique markers for population and phylogenetic analysis and further functional studies of these genes may answer some questions about sex determination, male fertility and Y chromosome evolution in this important species.

Normative data of the Barratt Impulsiveness Scale 11 (BIS-11) for Brazilian adults.

OBJECTIVE: The Barratt Impulsiveness Scale (BIS-11) is a valid and reliable instrument, and one of the most often used tools to assess impulsivity. This study assesses the performance of a large sample of adults by using a version of BIS-11 adapted to Brazilian Portuguese. METHODS: We assessed 3,053 adults from eight Brazilian states. Internal consistencies and performance data were presented for two correction criteria of BIS-11: original and the two-factor score. RESULTS: The associations between age, sex, region, and education and the BIS-11 scores present very small effect sizes. Therefore, we provided a percentile rank parameter for the different BIS-11 subscores considering the whole sample. Given the internal consistency of the two correction systems, we found that only the two-factor system fulfills the psychometric criteria of Cronbach's alpha (cutoff value of at least 0.6). CONCLUSION: Our results support the use of the Brazilian adaptation of BIS-11 in different regions of the country as a measure of impulsivity. Since high impulsiveness is a characteristic of several dysfunctional behaviors, the establishment of normative parameters is of utmost relevance and should be extended to other age ranges and populations in future studies.

Interneuronal calcium channel abnormalities in posttraumatic epileptogenic neocortex.

Decreased release probability (Pr) and increased failure rate for monosynaptic inhibitory postsynaptic currents (IPSCs) indicate abnormalities in presynaptic inhibitory terminals on pyramidal (Pyr) neurons of the undercut (UC) model of posttraumatic epileptogenesis. These indices of inhibition are normalized in high [Ca++] ACSF, suggesting dysfunction of Ca2+ channels in GABAergic terminals. We tested this hypothesis using selective blockers of P/Q and N-type Ca2+ channels whose activation underlies transmitter release in cortical inhibitory terminals. Pharmacologically isolated monosynaptic IPSCs were evoked in layer V Pyr cells by extracellular stimuli in adult rat sensorimotor cortical slices. Local perfusion of 0.2/1 µM ω-agatoxin IVa and/or 1 µM ω-conotoxin GVIA was used to block P/Q and N-type calcium channels, respectively. In control layer V Pyr cells, peak amplitude of eIPSCs was decreased by ~50% after treatment with either 1 µM ω-conotoxin GVIA or 1 µM ω-agatoxin IVa. In contrast, there was a lack of sensitivity to 1 µM ω-conotoxin GVIA in UCs. Immunocytochemical results confirmed decreased perisomatic density of N-channels on Pyr cells in UCs. We suggest that decreased calcium influx via N-type channels in presynaptic GABAergic terminals is a mechanism contributing to decreased inhibitory input onto layer V Pyr cells in this model of cortical posttraumatic epileptogenesis.

Targets for preventing epilepsy following cortical injury.

Prophylaxis of posttraumatic epilepsy will require a detailed knowledge of the epileptogenic pathophysiological processes that follow brain injury. Results from studies of experimental models and human epilepsy highlight alterations in GABAergic interneurons and formation of excessive new excitatory synaptic connectivity as prominent targets for prophylactic therapies. Promising laboratory results suggest that it will be possible to experimentally modify these aberrant processes and interfere with epileptogenesis. However, a number of key issues must be addressed before these results can be used to frame clinical antiepileptogenic therapy.

Presynaptic inhibitory terminals are functionally abnormal in a rat model of posttraumatic epilepsy.

Partially isolated "undercut" neocortex with intact pial circulation is a well-established model of posttraumatic epileptogenesis. Results of previous experiments showed a decreased frequency of miniature inhibitory postsynaptic currents (mIPSCs) in layer V pyramidal (Pyr) neurons of undercuts. We further examined possible functional abnormalities in GABAergic inhibition in rat epileptogenic neocortical slices in vitro by recording whole cell monosynaptic IPSCs in layer V Pyr cells and fast-spiking (FS) GABAergic interneurons using a paired pulse paradigm. Compared with controls, IPSCs in Pyr neurons of injured slices showed increased threshold and decreased peak amplitude at threshold, decreased input/output slopes, increased failure rates, and a shift from paired pulse depression toward paired pulse facilitation (increased paired pulse ratio or PPR). Increasing [Ca(2+)](o) from 2 to 4 mM partially reversed these abnormalities in Pyr cells of the epileptogenic tissue. IPSCs onto FS cells also had an increased PPR and failures. Blockade of GABA(B) receptors did not affect the paired results. These findings suggest that there are functional alterations in GABAergic presynaptic terminals onto both Pyr and FS cells in this model of posttraumatic epileptogenesis.

Impact of protein kinase C activation on epileptiform activity in the hippocampal slice.

There is evidence suggesting that protein kinase C (PKC) activation can prevent the enhanced network excitability associated with status epilepticus and group I metabotropic glutamate receptor (mGluR)-induced epileptogenesis. However, we observed no suppression of mGluR-induced burst prolongation in the guinea pig hippocampal slice when applied in the presence of the PKC activator phorbol-12,13-dibutyrate (PDBu). Furthermore, PDBu alone converted picrotoxin-induced interictal bursts into ictal-length discharges ranging from 2 to 6s in length. This effect could not be elicited by the inactive analog 4-alpha-PDBu and was suppressed with the PKC inhibitor chelerythrine, indicating PKC dependence. PKC activation can enhance neurotransmitter release, and both glutamate and acetylcholine are capable of eliciting similar prolonged synchronized discharges. However, neither mGluR1 nor NMDA receptor antagonist suppressed PDBu-driven burst prolongation, suggesting that increased glutamate release alone is unlikely to account for the PKC-induced expression of ictaform discharges. Similarly, atropine, a broad-spectrum muscarinic receptor antagonist, had no effect on PKC-induced burst prolongation. By contrast, AMPA/kainate receptor antagonist abolished PKC-induced burst prolongation, and mGluR5 antagonist significantly blunted the maximum burst length induced by PKC. These data suggest that PKC-induced prolongation of epileptiform bursts is dependent on changes specific to mGluR5 and AMPA/kainate receptors and not mediated simply by a generalized increase in transmitter release.

Avaliação eletrofisiológica in vitro de drogas antiepilépticas em fatias hipocampais humanas provenientes de pacientes portadores de epilepsia do lobo temporal refratária ao tratamento medicamentoso / In vitro electrophysiological assessment of antiepileptic drugs in human hippocampal slices originating from patients with refractory temporal lobe epilepsy

The absence of a satisfactory response to antiepileptic drug (AED) therapy, is an unresolved problem in a significant number of epileptic patients. Mechanisms of intractability are not well understood but may include a combination of poor penetration of AED across a functionally altered blood-brain barrier owing to increased expression of multiple drug resistance transporters. Therefore, the aim of this work was to assess the in vitro efficacy of antiepileptic drugs through human hippocampal slices originating from patients with refractory temporal lobe epilepsy submitted to corticoamygdalohippocampectomy. Slices was prepared from a 1 cm3 block of the hippocampus body 30 min after resection. Briefly, hippocampal slices of 400 µM thickness was cut coronally. Extracellular field potentials was recorded from the st. Granulosum of the dentate gyrus. The antiepileptic drugs added in the bath were Carbamazepine, Topiramate and Phenytoin. The phenytoin was effective reducing the hyperexcitability (polispikes) in 60% of the experiments (n = 5). On the other hand, the carbamazepine promoted a decrease in evoked epileptiform activity in 37,5% of the cases (n = 8). The application of topiramate in the bath reduced in 30% the number of polispikes (n = 10). Our results showed that the phenytoin application resulted in a significant reduction in neuronal excitability, however, the carbamazepine and topiramate were not able to control of the hiperexcitability, suggesting that local neuronal alterations, as well changes in blood brain barrier, could be responsible for such behaviors.

Pro-epileptic effect of alfentanil in rats subjected to pilocarpine-induced chronic epilepsy.

Pharmacological induction of epileptiform activity is a complementary method to study the epileptogenic area in drug-resistant epileptic patients. Among the different activation methods, fentanyl derivatives (e.g. alfentanil) provide one of the most efficient tools in triggering epileptiform abnormalities in surgical candidates. In this study, we tested the pro-epileptic effect of different concentrations of alfentanil in hippocampal slices obtained from control and pilocarpine-treated chronic epileptic rats. The pro-convulsant action of alfentanil was also studied in control and pilocarpine-treated epileptic rats implanted with subdural and hippocampal electrodes for electroencephalographic recordings. In 90% of slices from control animals, application of alfentanil (0.1-5 microM) induced a significant enhancement in amplitude and number of population spikes recorded in the hippocampal CA1 region. In contrast, alfentanil produced a significant reduction in the amplitude of population spikes in slices from pilocarpine-treated epileptic rats. These changes were accompanied by a significant increase in the number of population spikes in the form of epileptiform multispike responses of epileptic slices. Naloxone (20 microM) antagonized the effect of alfentanil in both control and epileptic slices, reducing the number of population spikes in slices from epileptic rats. In control rats, alfentanil induced epileptiform abnormalities in the hippocampal and cortical electroencephalographic recordings but only at concentrations higher than 200 microg/kg (e.g. 350 microg/kg). Lower doses of alfentanil (25 microg/kg) elicited epileptiform abnormalities only in chronic epileptic rats. The potent action of a minimal dose of alfentanil in inducing epileptiform activity suggests an enhancement of the pro-convulsant action of mu-receptor opioids in chronic temporal lobe epilepsy.